Fuel air explosive canister

ABSTRACT

A fuel-air explosive apparatus comprising a standard plastic beverage  bot, a plastic burster tube, a conventional detonator, a detonating cord, Teflon® tape and a liquid fuel. All of the components of the fuel-air explosive apparatus are readily available, standard materials.

GOVERNMENTAL INTEREST

The invention described herein may be manufactured, used and licensed byor for the U.S. Government without payment to me of any royalty thereon.

BACKGROUND OF THE INVENTION

The present invention deals with an improved fuel-air explosive canisterwhich is used solely for experimental purposes. Said fuel-air explosivecanister apparatus may be built using readily available, inexpensivematerials. The present invention employs conventional, plastic softdrink bottles, such as those set forth in U.S. Pat. No. 3,733,309,issued to Wyeth et al. Use of these materials makes experimentation inthe fuel-air explosive art easily attainable and cost efficient.

Difficulties associated with combustible fuel-air dispersion devicesinclude the extensive, for example machine shop, work required for themanufacture and assembly of fuel-air explosive devices. Moreover, priorart fuel-air explosive devices generally were constructed using variousamounts of metal and/or glass materials. Use of these materials cancause danger of fragmentation.

U.S. Pat. No. 3,596,602, issued to Gey et al., teaches a method andapparatus for delivering biological and chemical warfare agents usingfuel-air explosive. The teaching is silent as to the composition of thedelivery system per se. General mention is made to the use of canistersin the employ of said invention. Specific canisters, however, which maybe employed by Gey et al. have not been set forth. Moreover, theteaching is not directed to fuel-air experimental devices. Nor is Gey etal. directed to a device having as basic a structure as the presentinvention.

U.S. Pat. No. 3,730,093, issued to Cummings, teaches a fuel-airexplosive weapon improved by its use of implosion. Applicant is unawareof any fuel-air weapon, to date, which employs implosion. One of thenumerous fuels which may be employed therein is propylene oxide. Thepreferred embodiment employs a cylindrical plastic container which has acircular bottom end plate and a top plate, each of which may be composedof various metallic materials. Moreover, the device further requires thepresence of a layer of high explosives around the housing of thefuel-air explosive device. The device taught therein is more complexthan that employed by the present invention.

U.S. Pat. No. 4,157,928, issued to Falterman et al., relates to improvedfuels for fuel-air explosive weapons. The fuel-air explosive devicedescribed employs a metallic container. The teaching is silent as to theuse of plastic containers, not to mention the employ of conventional,plastic beverage bottles. The reference concentrates on the compositionof the fuel employed therein.

Well known fuel-air type devices are further described in U.S. Pat. No.4,132,169, issued to Gay et al. The devices taught contain two separate,sealed, concentrically arranged chambers. Within the central chamber ishoused a low brisance explosive. The device is primarily constructed ofmetallic materials. The device taught by Gay et al. requires moreoperating component parts than that of the present invention. Thecomplexity of the present invention is nowhere near that of Gay et al.

The closest prior art teaching is set forth in Statutory InventionRegistration (SIR) Number H161, issued to the inventor of the presentinvention. SIR H161 teaches a scaled down testing of explosive chemicalsusing a small fuel-air explosive plastic bottle. The bottle holds 264 mlof liquid fuel; it has a threaded cap with a hole running through itscenter to facilitate electrical wires from a detonator; and employs acentrifuge tube having a flange lip for a seal. The teaching thereindoes not employ readily available materials--264 ml bottles, threadedcaps having a hole, etc.

The present invention employs readily available materials which may beunobviously combined to form the present invention. The fuel-airexplosive device herein may be assembled without employing, forinstance, complex machine shop equipment or welding. In addition, theconstruction of the present invention is devoid of metal and glassmaterials, hence the hazard associated with the fragmentation of theapparatus is reduced, if not eliminated.

The present invention provides for a non-complex, fuel-air explosivedevice intended solely for experimental purposes.

BRIEF DESCRIPTION OF THE INVENTION

The present invention relates to a fuel-air explosive apparatus whichcomprises a readily available standard plastic beverage (soft drink)bottle, a plastic burster tube, a conventional detonator, a detonatingcord, Teflon® tape and liquid fuel. The novelty of the invention residesin the unobvious combination of these conventional component parts.

The present invention provides a means for constructing, forexperimental purposes, a fuel-air explosive apparatus which may beconstructed from materials which are inexpensive as well as readilyavailable. Moreover construction of the present invention does notrequire the use of highly technical machine shop devices, or othercomplex tools. It is simply constructed by hand.

Accordingly, it is an object of the present invention to provide afuel-air explosive apparatus which is used solely for experimentalpurposes.

It is a further object of the invention to provide a fuel-air explosiveapparatus which may be tested on small ranges that cannot accommodatethe safe testing of weapon size fuel-air explosive devices.

It is a further object of the invention to provide a fuel-air explosiveapparatus which may be constructed using conventional and readilyavailable component parts.

It is a further object of the invention to provide a fuel-air explosivedevice which may be assembled without employing complex machine shopequipment or welding apparatus.

It is still a further object of the invention to provide a fuel-airexplosive apparatus which is devoid of metal and glass materials.

Still a further object of the invention is to provide a leakprooffuel-air device for use in detonation physics and operations research.

Other objectives of the present invention will be apparent from thefollowing detailed description of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The invention comprises a fuel-air explosive device which employs aconventional, readily available standard plastic beverage bottle--i.e.0.5-liter, 1-liter, 1.5-liter, 2-liter or 3-liter soda bottle; a plasticburster tube--i.e., PVC; a conventional detonator; a detonating cord;Teflon® tape and liquid fuel.

The soft drink industry has universally standardized its plasticcontainers. All brands share the same general design and the same sizes.These bottles are able to withstand commercial handling and are of anideal size for experimentation. These plastic containers can be found invarious sizes--0.5-liter, 1-liter, 1.5-liter, 2-liter and 3-liter. All,but the 3-liter plastic container, share the 1/2 inch cap size and neck.

Commercial plastic plumbing pipes are available in sizes which aresuitable to render a close sliding fit within the neck of these sizebottles. This plumbing pipe, preferably made of PVC, is employed as abursting tube and in the following fashion. It is sealed at one endusing preferably a conventional epoxy cement. The sealed end is insertedinto the plastic bottle until it rests at the bottom therein. The pipeis then cut so that it is a certain length which allows approximatelyone inch of the pipe to extend above the bottle neck. The pipe shouldthen be marked using a pencil to draw a line to indicate the locationwhere the pipe emerges out of the bottle neck.

At this pencil mark, continuing approximately 3/4 of an inch below it,Teflon® tape having a width of approximately 1/2 inch is wound aroundthe tube. The Teflon® tape facilitates a snug fit of the plastic pipewithin the plastic bottle neck. The plastic pipe/tube is engaged inplace with a moderately forceful twist and push towards the bottom ofthe bottle. Although a locating cup may be employed at the bottom of thebottle to hold the plastic pipe in position, it is not deemed necessary.The neck length of the universal bottle is sufficient to hold theplastic burster, pipe/tube in a central position.

If one wishes, a fill mark can be labelled using conventional means,i.e. wax pencil, on the shoulder of the plastic bottle. This may beaccomplished by filling the bottle with water and inserting the plasticpipe therein. Once the plastic pipe is inserted, the water willoverflow. After this has occurred, the plastic pipe is withdrawn and thelevel at which the remaining water is present is where the fill markshould be labelled. Because the fuels which may be employed herein arepotentially harmful, this procedure is advised to secure againstspillage. One fuel that is most often employed in the fuel-air explosiveart is propylene oxide. However, any fuel that is liquid at normaltemperature and pressure is a candidate for use within the scope of thisinvention.

The plastic burster tube contains therein a detonating cord and adetonator. These individual components are conventional in the art. Theopen, top portion of the burster tube is packed closed using an inertand conventional duct-sealant putty of the type which may be employed inthe electrical and plumbing arts. The detonating cord employed isapproximately 1/100 to 1/250 the weight of the fuel used. Detonatorwires extend through the putty sealant and are connected to aconventional electric firing line. When the electric firing line causesthe detonator to explode the detonating cord, the shock wave and theexpanding gases caused thereby break the plastic bottle apart and propelthe liquid fuel therein outwards. The liquid fuel atomizes against theair and the fuel droplets then rapidly form a cloud of a fuel-airmixture.

Note that the conventional detonating cord, which may be employed, is aplastic jacket wrapped around a core of powdered explosive. Thispowdered explosive, upon detonation, changes to hot, expanding gas whichgenerates the shock wave described above.

This cloud is then detonated by a blast from approximately 50 to 220grams of conventional high explosive, which is located proximate to thebottle so as to be within the cloud. Among the explosives suitable forthis purpose are military high explosives, such as Compsition C-4,Composition B, or Pentolite. The explosive employed is detonated at apredetermined, appropriate delay time after the firing of the detonatorin the burster tube.

The delay time feature is a feature common to the fuel-air explosive artarea; and the optimum delay time may be determined experimentally. Thenecessary delay time lengthens as bottle size increases. This delayallows time for the expanding cloud to assume a size wherein there is acombustible ratio of fuel weight to air weight. An initial, trial delaytime is dialed into a conventional electric time delay generator, whichcloses the firing line circuit to the electric detonator present withinthe proximate high explosive. The entire cloud is thereby caused todetonate. One having ordinary skill in the fuel-air explosive art wouldbe familiar with the operation of a delay time feature.

The above description may be applied to the use of a conventional,plastic 3-liter beverage bottle; however, the plastic pipe/tube employedto form the burster tube should be approximately 3/4 inch plastic pipe(i.e. PVC pipe). More wrapping of Teflon® tape around the pipe is usedto serve the same purpose described above.

Other features of the present invention will be apparent from thefollowing drawing and its description.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a schematic representation of a fuel-air explosive devicewithin the scope of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

The drawing will be further discussed in order to provide a betterunderstanding and description of the present invention.

FIG. 1 illustrates a schematic representation of a fuel-air explosivedevice 19 within the scope of the present invention. Said fuel-airexplosive device 19 employs a plastic, standardized soft drink bottle12, which may be of various available and standard sizes--i.e., 0.5-,1-, 1.5- 2- or 3-liter. Within bottle neck 21, a commercial plastic pipe(i.e. PVC pipe) 10, which will additionally be referred to as a burstertube, is slideably inserted.

Said burster tube 10 may be sealed at the end entering into said bottle12 with epoxy cement 11 so as to form a leakproof seal. Once the sealedburster tube 10 has been completely inserted and touching the bottom ofsaid bottle 12, it 10 is cut preferably at approximately one inch 23above the bottle 12 height. With the burster tube 10 still in placewithin the bottle 12, a mark should be drawn onto said burster tube 10so as to indicate the location in which the burster tube 10 emerges fromsaid bottle neck 21.

The burster tube 10 is then removed from the bottle 12; and 1/2 inchTeflon® tape 13 is wound once or twice around the tube 10 beginning atsaid mark in which the tube 10 emerges from the plastic bottle 12. TheTeflon® tape 13 should extend from the ring mark down approximately 3/4inch in the direction of the bottle neck 21. Said tape 13 will provide aseal between the tube 10 and the neck 21 of the bottle.

The burster tube 10 is loaded with detonating cord 14 and a detonator15. The top of burster tube 10 is packed closed with an inertduct-sealant putty 16. Note that detonator wires 25 extend through putty16. The type of putty 16 which is employed is that which is conventionalin the electrical and plumbing arts. These detonator wires 25 areattached to an electric firing line (not shown).

When detonating cord 14 is activated, the resulting shock wave andexpanded gases (not shown, but previously described) created by theactivation break the bottle 12 and push out the liquid fuel 17. Becauseits 17 movement is resisted by the surrounding air, the liquid fuel 17is atomized into droplets and subsequently forms a cloud of fuel-air tobe later detonated by 50 to 220 grams of a high explosive (not shown)which is set to detonate at a specific delay time.

SPECIFIC EMBODIMENT OF THE INVENTION

A plastic, two-liter soft drink bottle (soda bottle) is employed in thisspecific example. Thirteen inches of 1/2 inch polyvinyl chloride (PVC)tube is used as the burster tube. Into the burster tube is slidtwo-by-nine inches of 100 grain/foot detonating cord with a detonatortaped thereto. (Detonating cords, such as Primacord® or Detacord®,manufactured by Ensign Bickford Company of Simsbury, Conn., may beemployed.) The top end of the burster tube is then packed to a depth ofone or two inches with a conventional duct-work putty.

The apparatus of the invention as used herein creates a dispersion ofthe propylene oxide, which at 66 milliseconds after bottle break,appears as a white cloud having a radius of approximately 7.0 feet. Saidcloud has a thickness at its central point of several 2-liter beveragebottle heights. This white cloud is to be detonated using one quarterpound of Composition C-4 electrically detonated at a delay time of 66milliseconds but not less than 50 milliseconds, and certainly no longerthan 80 milliseconds. The C-4 is placed at approximately 3-3.5 feet fromthe side of the bottle.

These specific parameters may be adjusted to serve the individual needsof the user. They have to be altered, in addition, depending upon thesize of the plastic bottle employed. Consideration should be given tothe effect of the fuels and/or solvents on the bottle and burster tube.For instance, the preferred fuel, propylene oxide, is a powerfulsolvent, as are most candidate fuels. They affect the resin of plasticbeverage bottles (i.e., those made of polyethylene terephthalate) aswell as PVC burster tubes. After one to two days, a 2-liter beveragebottle containing propylene oxide will shrink to have a volume of merely1.4 liters. Hence, when propylene oxide is employed, it should be filledinto the bottle just prior to use. These and numerous otherconsiderations should be evaluated prior to employing the apparatus ofthe invention.

Numerous types of burster tubes, caps and seals for the burster tubeshave been tested. They have all been proven to be unsatisfactory againstleaks resulting from the employ of solvent fuels. Use of Teflon® tape toseal the burster tube to the plastic bottle was the only successfulsolution to effectuate a proper seal for the present invention.

While particular embodiments of the present invention have been shownand described, it will be obvious to those skilled in the art thatchanges and modifications may be made without departing from thisinvention. Therefore, it is intended that the claims herein are toinclude all such obvious changes and modifications as fall within thetrue spirit and scope of this invention.

I claim:
 1. A fuel-air explosive apparatus comprisinga standard sized,plastic beverage bottle; a liquid fuel; a plastic burster tube; adetonator; a detonating cord; and sealant tape,wherein said standardsized, plastic beverage bottle contains therein said liquid fuel;wherein said plastic burster tube contains therein said detonator andsaid detonating cord; wherein said burster tube and its contents areinserted into the opening of said beverage bottle; and wherein saidsealant tape facilitates a snug fit of said plastic burster tube withinsaid standard sized, plastic beverage bottle.
 2. A fuel-air explosiveapparatus as set forth in claim 1, wherein said standard sized, plasticbeverage bottle is of a size selected from the group consisting of0.5-liter, 1-liter, 1.5-liters, 2-liters and 3-liters.
 3. A fuel-airexplosive apparatus as set forth in claim 1, wherein said liquid fuel ispropylene oxide.
 4. A fuel-air explosive apparatus as set forth in claim1, wherein said plastic burster tube is polyvinyl chloride (PVC) tubinghaving a diameter of approximately 0.5 to 0.75 inches.
 5. A fuel-airexplosive apparatus as set forth in claim 1, wherein said sealant tapeis Teflon®.